Efficient interleaver design for polar codes

Abstract

Aspects of the disclosure relate to wireless communication devices configured to encode information blocks to produce code blocks and interleave the code blocks utilizing an interleaver including a plurality of rows and a plurality of columns, where the number of columns of the interleaver varies between the rows. In some examples, the interleaver includes a right isosceles triangle-shaped matrix of rows and columns. In other examples, the interleaver includes a trapezoid-shaped matrix of rows and columns.

What is claimed is: 
     
       1. A method of wireless communication at a transmitting wireless communication device, comprising:
 encoding an information block using a polar encoder to produce a code block comprising a plurality of coded bits; 
 interleaving the plurality of coded bits utilizing an interleaver to produce an interleaved code block, wherein the interleaver comprises a plurality of rows and a plurality of columns, wherein a number of the plurality of columns varies between the plurality of rows; 
 modulating the interleaved code block to produce modulation symbols; and 
 transmitting the modulation symbols to a receiving wireless communication device over a wireless air interface; 
 wherein a number of columns in a first row of the plurality of rows is selected based on a number of the plurality of coded bits in the code block; 
 wherein a number of rows in a first column of the plurality of columns comprises a smallest integer P that satisfies an equation P*(P+1)/2≥N, where N comprises the number of the plurality of coded bits in the code block. 
 
     
     
       2. The method of  claim 1 , wherein the code block comprises the plurality of coded bits after puncturing. 
     
     
       3. The method of  claim 1 , wherein the number of columns in the first row and the number of rows in the first column are equal. 
     
     
       4. The method of  claim 1 , wherein interleaving the plurality of coded bits further comprises:
 feeding the plurality of coded bits into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows; and 
 reading out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; 
 wherein a first one of the coded bits in the first row is a first one of the coded bits in the first column. 
 
     
     
       5. The method of  claim 4 , wherein a second number of the plurality of coded bits between adjacent ones of the plurality of coded bits within adjacent ones of the plurality of rows varies between the plurality of rows. 
     
     
       6. The method of  claim 4 , wherein the interleaver comprises a right isosceles triangle-shaped matrix of the plurality of rows and the plurality of columns. 
     
     
       7. The method of  claim 4 , wherein interleaving the plurality of coded bits further comprises:
 inserting one or more null values into remaining ones of the plurality of rows after the plurality of coded bits are fed into the interleaver; and 
 skipping the one or more null values when reading out the plurality of coded bits. 
 
     
     
       8. The method of  claim 7 , wherein the interleaver comprises a trapezoid-shaped matrix of the plurality of rows and the plurality of columns excluding the remaining ones of the plurality of rows containing the one or more null values. 
     
     
       9. The method of  claim 1 , wherein interleaving the plurality of coded bits further comprises:
 inserting one or more null values into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows, wherein a number of the one or more null values is equal to a number of elements in a matrix comprising the plurality of rows and the plurality of columns less the number of the plurality of coded bits; 
 feeding the plurality of coded bits into remaining ones of the plurality of rows after the one or more null values are inserted into the interleaver; 
 reading out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; and 
 skipping the one or more null values when reading out the plurality of coded bits. 
 
     
     
       10. An apparatus configured for wireless communication, the apparatus comprising:
 a processor; 
 a transceiver coupled to the processor; and 
 a memory coupled to the processor, wherein the processor is configured to:
 encode an information block using a polar encoder to produce a code block comprising a plurality of coded bits; 
 interleave the plurality of coded bits utilizing an interleaver to produce an interleaved code block, wherein the interleaver comprises a plurality of rows and a plurality of columns, wherein a number of the plurality of columns varies between the plurality of rows; 
 modulate the interleaved code block to produce modulation symbols; and 
 transmit the modulation symbols to a receiving wireless communication device over a wireless air interface via the transceiver; 
 wherein a number of columns in a first row of the plurality of rows is selected based on a number of the plurality of coded bits in the code block; 
 wherein a number of rows in a first column of the plurality of columns comprises a smallest integer P that satisfies an equation P*(P+1)/2≥N, where N comprises the number of the plurality of coded bits in the code block. 
 
 
     
     
       11. The apparatus of  claim 10 , wherein the code block comprises the plurality of coded bits after puncturing. 
     
     
       12. The apparatus of  claim 10 , wherein the number of columns in the first row and the number of rows in the first column are equal. 
     
     
       13. The apparatus of  claim 10 , wherein the processor is further configured to:
 feed the plurality of coded bits into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows; and 
 read out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; 
 wherein a first one of the coded bits in the first row is a first one of the coded bits in the first column. 
 
     
     
       14. The apparatus of  claim 13 , wherein a second number of the plurality of coded bits between adjacent ones of the plurality of coded bits within adjacent ones of the plurality of rows varies between the plurality of rows. 
     
     
       15. The apparatus of  claim 13 , wherein the interleaver comprises a right isosceles triangle-shaped matrix of the plurality of rows and the plurality of columns. 
     
     
       16. The apparatus of  claim 13 , wherein the processor is further configured to:
 insert one or more null values into remaining ones of the plurality of rows after the plurality of coded bits are fed into the interleaver; and 
 skip the one or more null values when reading out the plurality of coded bits. 
 
     
     
       17. The apparatus of  claim 16 , wherein the interleaver comprises a trapezoid-shaped matrix of the plurality of rows and the plurality of columns excluding the remaining ones of the plurality of rows containing the one or more null values. 
     
     
       18. The apparatus of  claim 10 , wherein the processor is further configured to:
 insert one or more null values into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows, wherein a number of the one or more null values is equal to a number of elements in a matrix comprising the plurality of rows and the plurality of columns less the number of the plurality of coded bits; 
 feed the plurality of coded bits into remaining ones of the plurality of rows after the one or more null values are inserted into the interleaver; 
 read out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; and 
 skip the one or more null values when reading out the plurality of coded bits. 
 
     
     
       19. An apparatus configured for wireless communication, the apparatus comprising:
 means for polar encoding an information block to produce a code block comprising a plurality of coded bits; 
 means for interleaving the plurality of coded bits to produce an interleaved code block, wherein the means for interleaving comprises a plurality of rows and a plurality of columns, wherein a number of the plurality of columns varies between the plurality of rows; 
 means for modulating the interleaved code block to produce modulation symbols; and 
 means for transmitting the modulation symbols to a receiving wireless communication device over a wireless air interface; 
 wherein a number of columns in a first row of the plurality of rows is selected based on a number of the plurality of coded bits in the code block; 
 wherein a number of rows in a first column of the plurality of columns comprises a smallest integer P that satisfies an equation P*(P+1)/2≥N, where N comprises the number of the plurality of coded bits in the code block. 
 
     
     
       20. The apparatus of  claim 19 , wherein the code block comprises the plurality of coded bits after puncturing. 
     
     
       21. The apparatus of  claim 19 , wherein the number of columns in the first row and the number of rows in the first column are equal. 
     
     
       22. The apparatus of  claim 19 , wherein the means for interleaving the plurality of coded bits further comprises:
 means for feeding the plurality of coded bits into successive rows of the plurality of rows starting with the first row of the plurality of rows; and 
 means for reading out the plurality of coded bits from successive columns of the plurality of columns starting with the first column of the plurality of columns; 
 wherein a first one of the coded bits in the first row is a first one of the coded bits in the first column. 
 
     
     
       23. The apparatus of  claim 22 , wherein a second number of the plurality of coded bits between adjacent ones of the plurality of coded bits within adjacent ones of the plurality of rows varies between the plurality of rows. 
     
     
       24. The apparatus of  claim 22 , wherein the means for interleaving the plurality of coded bits further comprises:
 means for inserting one or more null values into remaining ones of the plurality of rows after the plurality of coded bits; and 
 means for skipping the one or more null values when reading out the plurality of coded bits. 
 
     
     
       25. The apparatus of  claim 19 , wherein the means for interleaving the plurality of coded bits further comprises:
 means for inserting one or more null values into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows, wherein a number of the one or more null values is equal to a number of elements in a matrix comprising the plurality of rows and the plurality of columns less the number of the plurality of coded bits; 
 means for feeding the plurality of coded bits into remaining ones of the plurality of rows after the one or more null values are inserted into the interleaver; 
 means for reading out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; and 
 means for skipping the one or more null values when reading out the plurality of coded bits. 
 
     
     
       26. A non-transitory computer-readable medium storing computer executable code, comprising code that when executed by a processor at a transmitting wireless communication device causes the transmitting wireless communication device to:
 encode an information block using a polar encoder to produce a code block comprising a plurality of coded bits; 
 interleave the plurality of coded bits utilizing an interleaver to produce an interleaved code block, wherein the interleaver comprises a plurality of rows and a plurality of columns, wherein a number of the plurality of columns varies between the plurality of rows; 
 modulate the interleaved code block to produce modulation symbols; and 
 transmit the modulation symbols to a receiving wireless communication device over a wireless air interface; 
 wherein a number of columns in a first row of the plurality of rows is selected based on a number of the plurality of coded bits in the code block; 
 wherein a number of rows in a first column of the plurality of columns comprises a smallest integer P that satisfies an equation P*(P+1)/2≥N, where N comprises the number of the plurality of coded bits in the code block. 
 
     
     
       27. The non-transitory computer-readable medium of  claim 26 , wherein the code block comprises the plurality of coded bits after puncturing. 
     
     
       28. The non-transitory computer-readable medium of  claim 26 , wherein the number of columns in the first row and the number of rows in the first column are equal. 
     
     
       29. The non-transitory computer-readable medium of  claim 26 , further comprising code for causing the transmitting wireless communication device to:
 feed the plurality of coded bits into successive rows of the plurality of rows of the interleaver starting with the first row of the plurality of rows; and 
 read out the plurality of coded bits from successive columns of the plurality of columns of the interleaver starting with the first column of the plurality of columns; 
 wherein a first one of the coded bits in the first row is a first one of the coded bits in the first column. 
 
     
     
       30. The non-transitory computer-readable medium of  claim 29 , wherein a second number of the plurality of coded bits between adjacent ones of the plurality of coded bits within adjacent ones of the plurality of rows varies between the plurality of rows.